Microsoft Corp is planning its biggest round of job cuts in five years, as the software maker looks to slim down and integrate Nokia Oyj’s handset unit, Bloomberg has reported, citing people with knowledge of the company’s plans. The reductions will probably be in engineering, marketing and areas of overlap with Nokia, said the people. The restructuring, which may be unveiled as soon as this week, may end up being the biggest in Microsoft history, topping the 5,800 jobs cut in 2009, two of the people said.